The efficiency of building, fabricating and/or remodeling a particular structure is dependant on the worker's ability to perform his or her task effectively and efficiently. This often means having the right tools readily available throughout a particular task or project. More specifically, the more the work environment can be improved, including the availability of specific tools, for safe and efficient performance by a worker, the better the final product is likely to be and the quicker it is likely to be obtained.
During the construction and/or remodeling of a particular structure, a worker (builder or fabricator) generally carries on his or her person (or keeps in close proximity to the work area) a variety of tools needed to perform and complete a specific task. These tools may be housed in compact tool boxes to be stored near the work area, or placed in larger tool cabinets readily accessible by the worker. In addition, as is very common in building construction, the tools may be carried in a tool belt worn about the worker's waist; in this regard, the tools are readily available when needed. In situations where only one or two tools may be required, the worker may simply choose to carry the tools in his or her pants pocket or coveralls to be used when needed.
To illustrate a particular construction task, one that is the topic of the present invention, a sheetrocker may carry a hammer, nails, cutting knife and/or rasping tool, all of which are generally needed to prepare and hang a single piece of sheetrock. Because a limited number of tools are required, the sheetrocker often chooses to carry these tools in a tool belt or in his or her pants pockets. During the sheetrock installation procedure, the sheetrocker will measure a section of sheetrock to be fitted to a particular area (e.g., a ceiling or a wall), score the sheetrock at the appropriate point (i.e., cut the outer sheetrock paper on at least one side of the sheetrock), break the sheetrock about the score (i.e., away from the cut) and finally cut the sheetrock paper on the opposite side of the sheetrock. Lastly, because the sheetrock is broken about the score (as opposed to being smoothly cut), there remains a jagged edge that must be rasped to properly prepare the sheetrock for installation against abutting surfaces such as other pieces of sheetrock, walls, floors and/or ceilings. In other words, the edges of the sheetrock, both cut and uncut, must closely abut one another with minimal gaps therebetween to be efficiently perfa-taped during the final finishing process. The more efficiently a sheetrocker can cut, rasp and hang the piece of sheetrock, the more expeditiously the task can be completed. This in turn reduces the overall cost and, in all likelihood, results in a higher quality final product.
Regarding the cutting and rasping procedure, a sheetrocker will generally use a conventional cutting knife to cut the outer paper of the sheetrock and a conventional rasp to smooth the jagged edges. An example of a typical cutting knife used for sheetrock preparation is shown and described in U.S. Pat. Nos. 3,107,426 to W. H. Robinson, Jr. and 3,888,002 to J. J. Graham. Such a cutting knife generally includes a handle member for being grasped by the user and a knife blade that is preferably extendable and retractable from and into the handle member. The cutting knives disclosed in these patents, while capable of being used for sheetrock preparation, may also be used for roofing, electrical wiring and/or as a general cutting knife in the building, construction and/or fabrication industries.
Another example of a cutting knife, specifically a cutting knife handle, is shown in U.S. Pat. No. 4,242,795 to E. J. Rollband et al. The Rollband et al. patent discloses a cutting knife handle having an extendable and retractable knife blade. A thumb button is provided that may be depressed to release the knife blade for either extending or retracting the knife blade from and into the handle member.
During the preparation and hanging of a piece of sheetrock, the sheetrocker, in succession, will generally use the cutting knife, the rasping tool, and the hammer and nails to complete the task of hanging a single piece of sheetrock. While the number of tools required may be minimal, misplacing a tool, leaving a needed tool behind or otherwise not having the proper tool available when needed can significantly inhibit the sheetrocker's performance, hence effecting the quality and cost of the final product. This is further complicated when the sheetrock preparation area is some distance from the sheetrock hanging area wherein the sheetrocker may waste valuable time retrieving a tool from the preparation area that is needed in the hang area and vise versa. Therefore, there is a need to minimize the number of tools a sheetrocker must carry to complete a specific task, such tools being combined or otherwise reduced in number, to minimize the probability that a tool may be left behind or otherwise not be available when needed.
Because a cutting knife, specifically the knife blade of the cutting knife, is used to cut a variety of abrasive materials including sheetrock, the knife blade may quickly become dull as a result of repeatedly cutting abrasive materials. In this regard, it may be necessary for a worker to carry replacement knife blades to replace worn or chipped knife blades. Alternatively, the worker may carry on his or her person a knife blade. sharpener used to sharpen the knife blade periodically. If the sheetrocker does not have replacement blades or a sharpener readily available, the worker may proceed to use a dull knife blade. As a result, the worker's effort in making a specific cut may increase and, as is accepted in the building industry, the worker is at a higher risk of injury when using a dull knife blade as opposed to a properly maintained knife blade. In this regard, there is a need for a relatively automatic and simple way to properly sharpen a knife blade. More specifically, there is a need for a sharpener that sharpens the knife blade as the knife blade is extended and retracted from and into the handle member.